Early life infections a player in celiac disease: study

Last Updated: 2015-09-18

By Megan Brooks

NEW YORK (Reuters Health) - Early life infections may indeed have a role in development of celiac disease in childhood, suggest results of the first large-scale population-based cohort study of this association.

"Children with the highest infection frequency in the first 18 months of life were at some 30% increased relative risk of later celiac disease as compared with children who had the lowest infection frequency, with an increasing risk according to number of infections," Dr. Karl Marild from the Norwegian Institute of Public Health in Oslo noted in email to Reuters Health.

"We found broadly consistently increased relative risk estimates for celiac disease in relation to different infection subtypes and according to infection frequency in the first 6 months of life and at age 6-18 months," he added.

Studies on early life infections and risk of later CD have generated mixed results, the investigators note online September 8 in the American Journal of Gastroenterology.

"Most, but not all, previous studies in this field have reported associations between early life infection and later celiac disease," Dr. Marild explained. "However these studies have mostly been restricted to inpatient infectious disease and thereby more susceptible to surveillance bias that may inflate risk estimates. Our results are consistent with these previous results but we contribute by showing that this association is not limited to inpatient infectious disease and by presenting risk estimates per type of infection."

The study team assessed ties between early life infections and CD risk using prospective population-based data from the Norwegian Mother and Child Cohort Study. They had data on repeated assessments of parent-reported infectious diseases up to 18 months of age for 72,921 children born between 2000 and 2009. Data on CD came from parental questionnaires and the Norwegian Patient Registry.

During a median follow-up period of 8.5 years, 581 children (0.8%) were diagnosed with CD.

They found that children with 10 or more infections up to age 18 months had a significantly higher risk of developing CD, relative to children with four or fewer infections (aOR=1.32).

Repeated lower (aOR=1.48) and upper (aOR=1.25) respiratory tract infections up to age 18 months were significantly associated with later CD, and gastrointestinal infections yielded "similar, but nonsignificant" increased relative risk estimates (aOR=1.13), the authors note.

"Additional adjustments for maternal CD, education level, smoking, birth weight, prematurity, infant feeding practices, birth season, and antibiotic treatment yielded largely unchanged results," they said.

This study, Dr. Marild told Reuters Health, "demonstrates that the association between infectious disease and later celiac disease is not due to potential confounders that previous studies were unable to adjust for, such as duration of breastfeeding and antibiotic treatment. The results are in line with exciting immunological data suggesting that repeated infections may trigger celiac disease."

Summing up, Dr. Marild said, "Our results may provide a somewhat better understanding to patients and practitioners on one significant aspect of the likely multi-factorial celiac disease etiology. However, I want to underline that we found overall only modestly increased relative risk estimates for celiac disease and that non-causal explanations for this association due to surveillance bias (i.e. increased diagnostic work-up for celiac disease in children suffering from high infection frequency) or reverse causation (that is the possibility that children with an undiagnosed celiac disease have an increased susceptibility to infections) cannot be excluded. Thus, our results should not alter the advice on the clinical follow-up of children with high infection frequency."

The study had no commercial funding and the authors have no relevant disclosures.

SOURCE: http://bit.ly/1NGFOhh

Am J Gastroenterol 2015.